For Redhat/CentOS/Fedora/SL distribution
Type the redhat-config-date command at the command line to start the time and date properties tool, run:
# redhat-config-date
OR type setup and select time zone configuration. This tool is recommended for remote ssh text based sessions.
# setup
Select timezone configuration. Just follow on screen instructions to change the timezone.
If you are using Debian / Ubuntu Linux
To change the timezone for you run the following command as root user:
# dpkg-reconfigure tzdata
Again, just follow on screen instructions.